In the food service, convenience store, and restaurant industries, ice and beverages are often dispensed into cups by equipment such as beverage towers or combination ice and beverage dispensers. Dispensing is typically controlled manually by applying pressure against a lever with the cup. This tends to be slow when employees are pouring the drinks, as it requires the operator stay with the machine and monitor the filling. When used in self-serve applications, there is a significant amount of waste due to overfilling. Also, because the individual monitoring the filling/pouring is preoccupied, he/she cannot attend to other activities often necessary in the food service business.
Dispensing equipment is available having the ability to provide accurate portions of ice and beverage (U.S. Pat. No. 5,058,773 to Brill et al.; U.S. Pat. No. 4,921,149 to Miller et al.). Typically, however, the operator must press a button corresponding to the size of the cup being presented for filling. Although this speeds up employee service, errors are occasionally made by pressing the wrong button. In addition, this type of equipment has been found to be unacceptable for self-serve use, as the general public is unfamiliar with the proper button to press.
It is desirable for dispensing equipment to be able to recognize the size of the cup being presented and deliver the correct amount of product, e.g., soft drink, automatically. As far back as 30 years ago, manually operated switches were used on dispensers to select one of several portion sizes. (U.S. Pat. No. 3,211,338 to Weil et al.) More recent attempts have been made to use multiple photo-detectors for this purpose. (U.S. Pat. No. 4,437,499 to Devale; U.S. Pat. No. 4,440,200 to Devale et al.; U.S. Pat. No. 5,491,333 to Skelletal.) While the hardware has changed overtime, the new systems have no capability for sensing the more recent wider variety of cups. These prior systems also have several other disadvantages that will become apparent.
Cups in the beverage industry tend to be produced in a limited number of diameters in order to minimize the number of different lids required. Different liquid capacities in cups of the same diameter are accomplished by varying the cup's height. Typical methods of construction of cups include waxed paper with a rolled lip at the top, or one piece molded foam or plastic. Although a variety of colors and graphics may be present on the sides, the top lip is universally light colored, and most often white.
The number of different cups used in restaurants and convenience stores has been increasing, and it is not uncommon to have five or more different size cups in use at the same location. Existing devices are typically limited to sensing three different size cups, placing them into categories such as "small," "medium," and "large." This limitation is due to physical constraints on the size of the sensor(s), as well as the complexity of the electronics and the cost. In many applications, therefore, currently available devices are incapable of sensing all of the cups in use. Also, several cups exist having a shorter height but larger diameter, and actually hold more liquid than prior taller cups. As a result, the potential exists for existing devices to register these as smaller cups, and thus inadequately fill the cups.
The exact height and liquid volume of each category of cup size varies from one restaurant to another, as there are several dozen different sizes in use throughout the industry. It is therefore necessary to make adjustments to the dispenser to provide the correct amount of product based on the actual cups in use at a particular location. These adjustments need to be repeated if a different cup is introduced, when servicing or replacing one of the sensing devices, or if the equipment is relocated. This is of particular concern to equipment owned by major beverage companies or leasing companies wherein such equipment is routinely refurbished and moved from one location to another.
Existing devices identify the size of the cups using infra-red light along the side of the cup. This results in variability in signal strength due to colors and graphics. In fact, these devices can fail to sense very dark colored cups due to the absorption of the light beam by the cup.
Finally, some of the current devices are composed of several assemblies located remotely from each other within the equipment, and interconnected by a network of wiring. Such devices are typically installed in new products by the manufacturer and do not lend themselves readily to field retrofitting onto or into existing equipment.